This disclosure is related to the field of seismic imaging of subsurface formations. More specifically, the disclosure concern locating spatial position of seismic diffractors in the subsurface from a wellbore, either while the wellbore is being drilled or thereafter.
Wellbore drilling through subsurface formations may be performed for the purpose of positioning such wellbores or parts thereof in formations containing useful materials such as hydrocarbons. Structures of the subsurface formations, and to some extent the composition of the formations may be determined by reflection seismic surveying techniques known in the art.
As a practical matter, reflection seismic surveying known in the art for determining structural and/or compositional features in the subsurface tend to emphasize features identifiable from specular reflections. It is known in the art that certain features in subsurface formations act as diffractors or scatters of seismic energy. In some cases, geologic properties associated with such diffractors may present drilling hazards or the properties of such diffractors may be economically useful. It is desirable to be able to determine the spatial position of such diffractors.